It's important to remember that while they are far more numerous, the working class is far less politically engaged and far less powerful than the other classes (who collectively constitute the "political" class), and because of this they're extremely easy to manipulate.I won't deny that the Dems have ignored the working class in general. Focusing on them to the exclusion of other core constituencies is not a viable solution.
I don't hold with this whole idea that the Democrats are anti-working class because they won't talk about economic issues. Conservatives don't talk to working class people about economic issues. They talk about social issues. Your average working class conservative doesn't give a single shit about the minimum wage, even if they're on minimum wage and would directly benefit from raising it. They care about whether insignificant numbers of Mexicans enter the country legally, or whether black people refuse to stand for the national anthem in a sports game. These things have absolutely no bearing on them, and that is the point. All of the efforts of the political class, the people who write the media they consume and set the political agenda, is focused on distracting the working class from things that actually matter.
The truth is, noone cares about the working class. You don't need the support or consent of the working class. You only need the support or consent of the the political class. The people who are politically engaged, who actually have power and influence, and who set the agenda that the working class follow.